Creamy Clam Chowder

Name: Creamy Clam Chowder
Ingredients: Fresh clams or clam meat with juices : 1 packet / 20 oz; Chopped onion (yellow) : 1 cup; Celery hearts (chopped) : 1 cup; 1 tablespoon butter; Garlic : minced 1 tbsp; Potatoes : peeled & cubed 2 cups; Butter : 3 tbsp; Flour : 3 tbsp; Milk / half and half : 3 cups; Cream : ½ cup; Salt and black pepper to taste; Herbs : freshly chopped parsley or dried thyme or rosemary (optional)